The invention relates to a series of N-heterocyclic compounds and derivatives useful as inhibitors of nitric oxide synthase (NOS) and to methods of therapy for various diseases employing those compounds.
Nitric oxide (NO) has been implicated in a number of diverse physiological processes, including smooth muscle relaxation, platelet inhibition, nerve transmission, immune regulation and penile erection. Nitric oxide is produced under various conditions by virtually all nucleated mammalian cells. A number of pathologies are ascribed to abnormalities in NO production including stroke, insulin dependent diabetes, septic shock-induced hypotension, rheumatoid arthritis and multiple sclerosis. Nitric oxide is synthesized in biological tissues by an enzyme called nitric oxide synthase (NOS) which uses NADPH and molecular oxygen to oxidize L-arginine to citrulline and NO.
Nitric oxide synthase exists in at least three isoforms, which fall into two primary categories: constitutive and inducible. Two constitutive isoforms, which are calcium and calmodulin dependent, have been identified, and one inducible isoform has been identified. The constitutive isoforms are (1) a neuronal isoform, NOS-1 or nNOS, which is found in the brain and skeletal muscles and (2) an endothelial isoform, NOS-3 or eNOS, which is expressed in the endothelium of blood vessels, the epithelium of the bronchial tree and in the brain. These constitutive isoforms are not the target of the NOS inhibitors of the present invention.
The inducible isoform (NOS-2 or iNOS) is expressed in virtually all nucleated mammalian cells following exposure to inflammatory cytokines or lipopolysaccharide. Its presence in macrophages and lung epithelial cells is particularly noteworthy. The inducible isoform is neither stimulated by calcium nor blocked by calmodulin antagonists. It contains several tightly bound co-factors, including FMN, FAD and tetrahydrobiopterin.
Nitric oxide generated by the inducible form of NOS has been implicated in the pathogenesis of inflammatory diseases. In experimental animals, hypotension induced by lipopolysaccharide or tumor necrosis factor a can be reversed by NOS inhibitors. Conditions which lead to cytokine-induced hypotension include septic shock, hemodialysis and interleukin therapy in cancer patients. It is expected that an INOS inhibitor would be effective in treating cytokine-induced hypotension. In addition, recent studies have suggested a role for NO in the pathogenesis of inflammation, and NOS inhibitors would therefore have beneficial effects on inflammatory bowel disease, cerebral ischemia and arthritis. Inhibitors of NOS may also be useful in treating adult respiratory distress syndrome (ARDS) and myocarditis, and they may be useful as adjuvants to short term immunosuppression in transplant therapy.
The diversity and ubiquity of NO function in physiology make the specific therapeutic targeting of NO-related phenomena an important consideration. Since endogenous NO production is the result of the actions of related but distinct isozymes, the differential inhibition of NOS isozymes allows more selective therapy with fewer side effects.
The compounds of the invention are inhibitors of iNOS and are therefore useful in conditions associated with the excessive production of NO. Accordingly, in one aspect, the invention is directed to compounds selected from the group consisting of the following formulae: 
wherein:
each Z1 is independently xe2x80x94(CH2)mxe2x80x94Oxe2x80x94 (where m is 0 to 2), xe2x80x94(CH2)mxe2x80x94Sxe2x80x94 (where m is 0 to 2), or xe2x80x94(CH2)mxe2x80x94N(R7)xe2x80x94 (where m is 0 to 2);
each Z2 is independently xe2x80x94Oxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), xe2x80x94Sxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), or xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2);
Z3 is xe2x80x94(CH2)nxe2x80x94 (where n is 1 to 4), xe2x80x94Oxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), xe2x80x94Sxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), or xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2);
each R1 and R3 are independently selected from the group consisting of hydrogen, halo, alkyl, haloalkyl, nitro, aralkoxy, xe2x80x94OR8, xe2x80x94R11xe2x80x94OR8, xe2x80x94N(R8)R9, xe2x80x94C(O)OR8, xe2x80x94R11xe2x80x94C(O)OR8, xe2x80x94C(O)N(R8)R9, xe2x80x94R11xe2x80x94C(O)N(R8)R9, xe2x80x94C(O)N(R8)CH2C(O)N(R8)R9, xe2x80x94N(R8)C(O)N(R8)R9, xe2x80x94N(R8)C(O)R9, xe2x80x94N(R8)S(O)2R10, and xe2x80x94N(R8)C(O)N(R8)xe2x80x94CH2C(O)N(R8)R9;
R2 is hydrogen, alkyl, bromo, iodo, xe2x80x94N(R7)xe2x80x94(CH2)pxe2x80x94N(R8)R9 (where p is 1 to 4), xe2x80x94(CH2)qxe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR8 (where q is 0 to 3), 4-morpholinyl, 1-piperidinyl, 1-piperazinyl, or 1-pyrrolidinyl;
each R4 is independently hydrogen or alkyl;
each R5 is independently hydrogen, halo, haloalkyl, alkyl, nitro, xe2x80x94OR8, xe2x80x94C(O)OR8, xe2x80x94C(O)N(R8)R9, xe2x80x94N(R8)R9, xe2x80x94N(R8)C(O)R8, or xe2x80x94N(H)S(O)2R10;
each R6 is independently hydrogen, alkyl, aryl, aralkyl, halo, xe2x80x94N(R8)R9, xe2x80x94N(R7)xe2x80x94(CH2)pxe2x80x94N(R8)R9 (where p is 1 to 4), xe2x80x94(CH2)qxe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)OR8 (where q is 0 to 3), 4-morpholinyl, 1-piperidinyl, 1-piperazinyl, or 1-pyrrolidinyl;
each R7 is hydrogen or alkyl;
each R8 and R9 is independently hydrogen, alkyl, aryl (optionally substituted by one or more substituents selected from the group consisting of halo, alkyl, aryl, aralkyl, hydroxy, alkoxy, aralkoxy, amino, dialkylamino, monoalkylamino, nitro, carboxy, alkoxycarbonyl, aminocarbonyl, monoalkylaminocarbonyl, and dialkylaminocarbonyl), or aralkyl (wherein the aryl is optionally substituted by one or more substituents selected from the group consisting of halo, alkyl, aryl, aralkyl, hydroxy, alkoxy, aralkoxy, amino, dialkylamino, monoalkylamino, nitro, carboxy, alkoxycarbonyl, aminocarbonyl, monoalkylaminocarbonyl, and dialkylaminocarbonyl);
each R10 is alkyl, aryl (optionally substituted by one or more substituents selected from the group consisting of halo, alkyl, aryl, aralkyl, hydroxy, alkoxy, aralkoxy, amino, dialkylamino, monoalkylamino, nitro, carboxy, alkoxycarbonyl, aminocarbonyl, monoalkylaminocarbonyl, and dialkylaminocarbonyl), or aralkyl (wherein the aryl is optionally substituted by one or more substituents selected from the group consisting of halo, alkyl, aryl, aralkyl, hydroxy, alkoxy, aralkoxy, amino, dialkylamino, monoalkylamino, nitro, carboxy, alkoxycarbonyl, aminocarbonyl, monoalkylaminocarbonyl, and dialkylaminocarbonyl), and
each R11 is independently an alkylene or alkylidene chain;
as a single stereoisomer or a mixture thereof; or a pharmaceutically acceptable salt thereof.
In another aspect, the invention is directed to pharmaceutical compositions useful in treating a condition in a mammal resulting from an abnormality in NO production, which compositions comprise a compound of the invention as described above and a pharmaceutically acceptable excipient.
In another aspect, the invention is directed to methods of treating a condition resulting from an abnormality in NO production which methods comprise administering to a mammal having a condition resulting from an abnormality in NO production a therapeutically effective amount of a compound of the invention as described above.
A. Definitions
As used in the specification and appended claims, unless specified to the contrary, the following terms have the meaning indicated:
xe2x80x9cAlkylxe2x80x9d refers to a straight or branched hydrocarbon chain radical consisting solely of carbon and hydrogen atoms, containing no unsaturation, having from one to six carbon atoms, and which is attached to the rest of the molecule by a single bond, e.g., methyl, ethyl, n-propyl, 1-methylethyl (iso-propyl), n-butyl, n-pentyl, 1,1-dimethylethyl (t-butyl), and the like.
xe2x80x9cAlkoxyxe2x80x9d refers to a radical of the formula xe2x80x94ORa where Ra is an alkyl radical as defined above, e.g., methoxy, ethoxy, n-propoxy, 1-methylethoxy (iso-propoxy), n-butoxy, n-pentoxy, 1,1-dimethylethoxy (t-butoxy), and the like.
xe2x80x9cAlkoxycarbonylxe2x80x9d refers to a radical of the formula xe2x80x94C(O)ORa where Ra is an alkyl radical as defined above, e.g., methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, 1-methylethoxycarbonyl(iso-propoxycarbonyl), n-butoxycarbonyl, n-pentoxycarbonyl, 1,1-dimethylethoxycarbonyl(t-butoxycarbonyl), and the like.
xe2x80x9cAminoxe2x80x9d refers to the radical xe2x80x94NH2.
xe2x80x9cArylxe2x80x9d refers to a phenyl or naphthyl radical.
xe2x80x9cAralkylxe2x80x9d refers to a radical of the formula xe2x80x94RaRb where Ra is an alkyl radical as defined above, substituted by Rb, an aryl radical, as defined above, e.g., benzyl.
xe2x80x9cArylcarbonylxe2x80x9d refers to a radical of the formula xe2x80x94C(O)xe2x80x94Rb where Rb is an aryl radical as defined above, e.g., phenylcarbonyl.
xe2x80x9cAralkoxyxe2x80x9d refers to a radical of the formula xe2x80x94ORc where Rc is an aralkyl radical as defined above, e.g., benzyloxy, and the like.
xe2x80x9cAminocarbonylxe2x80x9d refers to the radical xe2x80x94C(O)NH2.
xe2x80x9cCarboxyxe2x80x9d refers to the radical xe2x80x94C(O)OH.
xe2x80x9cDialkylaminoxe2x80x9d refers to a radical of the formula xe2x80x94N(Ra)Ra where each Ra is independently an alkyl radical as defined above, e.g., dimethylamino, methylethylamino, diethylamino, dipropylamino, ethylpropylamino, and the like.
xe2x80x9cDialkylaminocarbonylxe2x80x9d refers to a radical of the formula xe2x80x94C(O)N(Ra)Ra where each Ra is independently an alkyl radical as defined above, e.g., dimethylaminocarbonyl, methylethylaminocarbonyl, diethylaminocarbonyl, dipropylaminocarbonyl, ethylpropylaminocarbonyl, and the like.
xe2x80x9cHaloxe2x80x9d refers to bromo, chloro, iodo or fluoro.
xe2x80x9cHaloalkylxe2x80x9d refers to an alkyl radical, as defined above, that is substituted by one or more halo radicals, as defined above, e.g., trifluoromethyl, difluoromethyl, trichloromethyl, 2,2,2-trifluoroethyl, 1-fluoromethyl-2-fluoroethyl, 3-bromo-2-fluoropropyl, 1-bromomethyl-2-bromoethyl, and the like.
xe2x80x9cMammalxe2x80x9d includes humans and domesticated animals, including, without limitation, mice, rats, cattle, horses, swine, sheep, goats, dogs, cats, rabbits, and the like.
xe2x80x9cMonoalkylaminoxe2x80x9d refers to a radical of the formula xe2x80x94NHRa where Ra is an alkyl radical as defined above, e.g., methylamino, ethylamino, propylamino, and the like.
xe2x80x9cMonoalkylaminocarbonylxe2x80x9d refers to a radical of the formula xe2x80x94C(O)NHRa where Ra is an alkyl radical as defined above, e.g., methylaminocarbonyl, ethylaminocarbonyl, propylaminocarbonyl, and the like.
xe2x80x9cNitroxe2x80x9d refers to xe2x80x94NO2.
xe2x80x9cOptionalxe2x80x9d or xe2x80x9coptionallyxe2x80x9d means that the subsequently described event of circumstances may or may not occur, and that the description includes instances where said event or circumstance occurs and instances in which it does not. For example, xe2x80x9coptionally substituted arylxe2x80x9d means that the aryl radical may or may not be substituted and that the description includes both substituted aryl radicals and aryl radicals having no substitution.
xe2x80x9cPharmaceutically acceptable saltxe2x80x9d includes both acid and base addition salts.
xe2x80x9cPharmaceutically acceptable acid addition saltxe2x80x9d refers to those salts which retain the biological effectiveness and properties of the free bases, which are not biologically or otherwise undesirable, and which are formed with inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like, and organic acids such as acetic acid, trifluoroacetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, maleic acid, malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid, and the like.
xe2x80x9cPharmaceutically acceptable base addition saltxe2x80x9d refers to those salts which retain the biological effectiveness and properties of the free acids, which are not biologically or otherwise undesirable. These salts are prepared from addition of an inorganic base or an organic base to the free acid. Salts derived from inorganic bases include, but are not limited to, the sodium, potassium, lithium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, aluminum salts and the like. Preferred inorganic salts are the ammonium, sodium, potassium, calcium, and magnesium salts. Salts derived from organic bases include, but are not limited to, salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines and basic ion exchange resins, such as isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, ethanolamine, 2-dimethylaminoethanol, 2-diethylaminoethanol, dicyclohexylamine, lysine, arginine, histidine, caffeine, procaine, hydrabamine, choline, betaine, ethylenediamine, glucosamine, methylglucamine, theobromine, purines, piperazine, piperidine, N-ethylpiperidine, polyamine resins, and the like. Particularly preferred organic bases are isopropylamine, diethylamine, ethanolamine, trimethylamine, dicyclohexylamine, choline and caffeine.
xe2x80x9cTherapeutically effective amountxe2x80x9d refers to that amount of a compound of the invention which, when administered to a mammal, preferably a human, in need thereof, is sufficient to effect treatment, as defined below, for a condition resulting from an abnormality in NO production. The amount of a compound of the invention which constitutes a xe2x80x9ctherapeutically effective amountxe2x80x9d will vary depending on the compound, the condition and its severity, and the age of the mammal, preferably a human, to be treated, but can be determined routinely by one of ordinary skill in the art having regard to his own knowledge and to this disclosure.
xe2x80x9cTreatingxe2x80x9d or xe2x80x9ctreatmentxe2x80x9d as used herein covers the treatment of a condition in a mammal, preferably a human, which condition is characterized by an abnormality in NO production, and includes:
(i) preventing the condition from occurring in the mammal, in particular, when such mammal is predisposed to the condition but has not yet been diagnosed as having it;
(ii) inhibiting the condition, i.e., arresting its development; or
(iii) relieving the condition, i.e., causing regression of the condition.
The yield of each of the reactions described herein is expressed as a percentage of the theoretical yield.
The compounds of the invention, or their pharmaceutically acceptable salts may contain one or more asymmetric centers and may thus give rise to enantiomers, diastereomers, and other stereoisomeric forms that may be defined, in terms of absolute stereochemistry, as (R)- or (S)- or, as (D)- or (L)- for amino acids. The present invention is meant to include all such possible isomers, as well as, their racemic and optically pure forms. Optically active (R)- and (S)-, or (D)- and (L)- isomers may be prepared using chiral synthons or chiral reagents, or resolved using conventional techniques. When the compounds described herein contain olefinic double bonds or other centers of geometric asymmetry, and unless specified otherwise, it is intended that the compounds include both E and Z geometric isomers. Likewise, all tautomeric forms are also intended to be included.
The nomenclature used herein is a modified form of the I.U.P.A.C. nomenclature system wherein the compounds of the invention are named herein as derivatives of the central N-heterocyclic moiety. For example, the following compound of the invention: 
is named herein as 2-[(1,3-benzodioxol-5-yl)methyl]-6-[3-(dimethylamino)propyl(methyl)amino]-4-[4-(1H-imidazol-1-yl)phenoxy]-5-methylpyrimidine. Unless otherwise indicated, compound names are intended to include any single stereoisomer, enantiomer, racemate or mixtures thereof.
B. Utility of the Compounds of the Invention
Nitric oxide generated by the inducible form of nitric oxide synthase (iNOS) has been implicated in the pathogenesis of numerous inflammatory and autoimmune diseases and also in diseases which are generally not regarded as inflammatory, but nevertheless may involve cytokines which locally up-regulate iNOS. The compounds of the invention, alone or in combination with other pharmaceutical agents, are therefore useful in treating mammals, preferably humans, having a condition resulting from an abnormality in NO production. Such conditions include, but are not limited to, the following:
Multiple sclerosis (Parkinson, J. F. et al., J. Mol. Med. (1997), Vol. 75, pp. 174-186); stroke or cerebral ischemia (Iadecola, C. et al., J. Neurosci. (1997), Vol. 17, pp. 9157-9164); Alzheimer""s disease (Smith, M. A. et al., J. Neurosci. (1997), Vol. 17, pp. 2653-2657; Wallace, M. N. et al., Exp. Neurol. (1997), Vol. 144, pp. 266-272); HIV dementia (Adamson, D. C. et al., Science (1996), Vol. 274, pp. 1917-1921); Parkinson""s disease (Hunot, S. et al, Neuroscience (1996), Vol. 72, pp. 355-363); meningitis (Koedel, U. et al., Ann. Neurol. (1995), Vol. 37, pp. 313-323); dilated cardiomyopathy and congestive heart failure (Satoh M et al., J. Am. Coll. Cardiol. (1997), Vol. 29, pp. 716-724); atherosclerosis (Wilcox, J. N. et al., Arterioscler. Thromb. Vasc. Biol. (1997), Vol. 17, pp. 2479-2488); restenosis or graft stenosis, septic shock and hypotension (Petros, A. et al., Cardiovasc. Res. (1994), Vol. 28, pp. 34-39); hemorrhagic shock (Thiemermann, C. et al., Proc. Natl. Acad. Sci. (1993), Vol. 90, pp. 267-271); asthma (Barnes, P. J., Ann. Med. (1995), Vol. 27, pp. 389-393; Flak, T. A. et al., Am. J. Respir. Crit. Care Med. (1996), Vol. 154, pp. S202-S206); adult respiratory distress syndrome, smoke or particulate-mediated lung injury (Ischiropoulos, H. et al., Am. J. Respir. Crit. Care Med. (1994), Vol. 150, pp. 337-341; Van Dyke, K., Agents Actions (1994), Vol. 41, pp. 44-49); pathogen-mediated pneumonias (Adler, H. et al., J. Exp. Med. (1997), Vol. 185, pp. 1533-1540); trauma of various etiologies (Thomae, K. R. et al., Surgery (1996), Vol. 119, pp. 61-66); rheumatoid arthritis and osteoarthritis (Grabowski, P. S. et al., Br. J. Rheumatol. (1997), Vol. 36, pp. 651-655); glomerulonephritis (Weinberg, J. B. et al., J. Exp. Med. (1994), Vol. 179, pp. 651-660); systemic lupus erythematosus (Belmont, H. M. et al., Arthritis Rheum. (1997), Vol. 40, pp. 1810-1816); inflammatory bowel diseases such as ulcerative colitis and Crohn""s disease (Godkin, A. J. et al., Eur. J. Clin. Invest. (1996), Vol. 26, pp. 867-872; Singer, I. I. et al., Gastroenterology (1996), Vol. 111, pp. 871-885); insulin dependent diabetes mellitus (McDaniel, M. L., et al., Proc. Soc. Exp. Biol. Med. (1996), Vol. 211, pp. 24-32); diabetic neuropathy or nephropathy (Sugimoto, K. and Yagihashi, S., Microvasc. Res. (1997), Vol. 53, pp. 105-112; Amore, A. et al., Kidney Int. (1997), Vol. 51, pp. 27-35); acute and chronic organ transplant rejection (Worrall, N. K. et al., Transplantation (1997), Vol. 63, pp. 1095-1101); transplant vasculopathies (Russell, M. E. et al., (1995), Vol. 92, pp. 457-464); graft-versus-host disease (Kichian, K. et al., J. Immunol. (1996), Vol. 157, pp. 2851-2856); psoriasis and other inflammatory skin diseases (Bruch-Gerharz, D. et al., J. Exp. Med. (1996), Vol. 184, pp. 2007-2012); and cancer (Thomsen, L. L. et al., Cancer Res. (1997), Vol. 57, pp. 3300-3304).
The compounds of the current invention may also be useful for the management of male and female reproductive functions when used alone or combined with other drugs commonly used for these indications. Examples, without implied limitation, include: inhibition of fertilization, endometrial receptivity and implantation (alone or in combination with a progesterone antagonist); post-coital contraception (alone or in combination with a progesterone antagonist); induction of abortion (in combination with an antiprogestin and in further combination with a prostaglandin); control and management of labor and delivery; treatment of cervical incompetence (alone or in combination with progesterone or a progestin); treatment of endometriosis (alone or in combination with other drugs, including LHRH-agonists/antagonists, antiprogestins or progestins by either sequential application or by concomitant administration). See, for example, the following references: Chwalisz, K. et al., J. Soc. Gynecol. Invest. (1997), Vol. 4, No. 1 (Supplement), page 104a, which discusses the inhibition of fertilization, endometrial receptivity and implantation, or post-coital contraception, alone or in combination with a progesterone antagonist; Chwalisz, K. et al., Prenat. Neonat. Med. (1996), Vol. 1, pp. 292-329, which discusses the induction of abortion, in combination with an antiprogestin and in further combination with a prostaglandin, and the control and management of labor and delivery; and Chwalisz, K. et al., Hum. Reprod. (1997), vol. 12, pp. 101-109, which discusses the treatment of cervical incompetence, alone or in combination with progesterone or a progestin.
Those skilled in the art will also recognize that the compounds of the present invention include 1-substituted imidazoles. This class of compounds has previously been described as mechanism-based, heme-binding inhibitors of the cytochrome P450 family of enzymes (Maurice, M. et al., FASEB J. (1992), Vol. 6, pp. 752-758) in addition to NO synthesis (Chabin, R. N M. et al., Biochemistry (1996), Vol. 35, pp. 9567-9575). The compounds of the present invention may thus be useful as inhibitors of selected cytochrome P450 family members of therapeutic interest including, but not limited to, P450 enzymes involved in steroid and retinoid biosynthesis (Masamura et al., Breast Cancer Res. Treat. (1995), Vol. 33, pp. 19-26; Swart, P. et al., J. Clin. Endocrinol. Metab., Vol. 77, pp. 98-102; Docks, P. et al., Br. J. Dermatol. (1995), Vol. 133, pp. 426-432) and cholesterol biosynthesis (Burton, P. M. et al., Biochem. Pharmacol. (1995), Vol. 50, pp. 529-544; and Swinney, D. C. et al., Biochemistry (1994), Vol. 33, pp. 4702-4713). Imidazole-based compounds may also have antifungal activity (Aoyama, Y. et al., Biochem. Pharmacol. (1992), Vol. 44, pp. 1701-1705).
C. Testing of the Compounds of the Invention
Nitric oxide synthases are complex enzymes that catalyze the conversion of L-arginine to NO and citrulline. Catalysis proceeds through two successive oxidations of the guanidinium group of L-arginine.
A cell-based NOS assay employing the measurement of NO oxidation product, nitrite, in the conditioned medium of cultured cells was employed for the evaluation of the compounds of the invention in vitro. The murine monocytic cell lines RAW 264.7 and J774 are well documented as capable of producing  greater than 10 xcexcM nitrite in response to immunostimulation. This in vitro assay is described in detail below in the Examples.
Various in vivo assays may be employed to determine the efficacy of the compounds of the invention in treating a condition resulting from an abnormality in NO production, such as arthritis. Such an assay is described in detail below in the Examples.
Those skilled in the art will also recognize that numerous assays for the activity of the NOS isoforms (iNOS, nNOS and eNOS) exist which can be used to evaluate the biological activity of the compounds of the current invention. These include assays for native NOS isoforms in tissues studied ex vivo (Mitchell et al., Br. J. Pharmacol. (1991), Vol. 104, pp. 289-291; Szabo et al., Br. J. Pharmacol. (1993), Vol. 108, pp. 786-792; Joly et al., Br. J. Pharmacol. (1995), Vol. 115, pp. 491-497) as well as primary cell cultures and cell lines (Forstermann et al., Eur. J. Pharmacol. (1992), Vol. 225, pp. 161-165; Radmoski et al., Cardiovasc. Res. (1993), Vol. 27, pp. 1380-1382; Wang et al., J. Pharmacol. Exp. Ther. (1994), Vol. 268, pp. 552-557). Those skilled in the art will also recognize that recombinant NOS enzymes can be expressed in heterologous cells by either transient transfection (Karlsen et al., Diabetes, (1995), Vol. 44, pp. 753-758), stable transfection (McMillan et al., Proc. Natl. Acad. Sci. (1992), Vol. 89, pp. 11141-11145; Sessa et al., J. Biol. Chem. (1995), Vol. 270, pp. 17641-17644) or via the use of lytic virus transfection (Busconi and Michel, Mol. Pharmacol. (1995), Vol. 47, pp. 655-659; List et al., Biochem. J. (1996), Vol. 315, pp. 57-63) using NOS cDNAs. Heterologous expression can be achieved in mammalian cells (McMillan et al., Proc. Natl. Acad. Sci. (1992), Vol. 89, pp. 11141-11145), insect cells (Busconi and Michel, Mol. Pharmacol. (1995), Vol. 47, pp. 655-659; List et al., Biochem. J. (1996), Vol. 315, pp. 57-63), yeast (Sari et al., Biochemistry (1996), Vol. 35, pp. 7204-7213) or bacteria (Roman et al., Proc. Natl. Acad. Sci. (1995), Vol. 92, pp. 8428-8432; Martasek et al., Biochem. Biophys. Res. Commun. (1996), Vol. 219, pp. 359-365). Any of these heterologous expression systems can be used to establish iNOS, nNOS and eNOS assay systems to evaluate the biological activity of the compounds of the present invention.
The P450 inhibitory activity of the compounds of the present invention can be assessed using appropriate assay systems specific for the P450 isoform of interest. Such assays are included in the references cited in the discussion of P450 family of enzymes in Paragraph B above. One additional example of mammalian cytochrome P450 isoform that may be inhibited by the compounds of the present invention is cytochrome P450 3A4 which can be assayed in a manner similar to the method described in Yamazaki et al., Carcinogenesis (1995), Vol. 16, pp. 2167-2170.
D. Administration of the Compounds of the Invention
Administration of the compounds of the invention, or their pharmaceutically acceptable salts, in pure form or in an appropriate pharmaceutical composition, can be carried out via any of the accepted modes of administration or agents for serving similar utilities. Thus, administration can be, for example, orally, nasally, parenterally, topically, transdermally, or rectally, in the form of solid, semi-solid, lyophilized powder, or liquid dosage forms, such as for example, tablets, suppositories, pills, soft elastic and hard gelatin capsules, powders, solutions, suspensions, or aerosols, or the like, preferably in unit dosage forms suitable for simple administration of precise dosages. The compositions will include a conventional pharmaceutical carrier or excipient and a compound of the invention as the/an active agent, and, in addition, may include other medicinal agents, pharmaceutical agents, carriers, adjuvants, etc.
Generally, depending on the intended mode of administration, the pharmaceutically acceptable compositions will contain about 1% to about 99% by weight of a compound(s) of the invention, or a pharmaceutically acceptable salt thereof, and 99% to 1% by weight of a suitable pharmaceutical excipient. Preferably, the composition will be about 5% to 75% by weight of a compound(s) of the invention, or a pharmaceutically acceptable salt thereof, with the rest being suitable pharmaceutical excipients.
The preferred route of administration is oral, using a convenient daily dosage regimen which can be adjusted according to the degree of severity of the disease-state to be treated. For such oral administration, a pharmaceutically acceptable composition containing a compound(s) of the invention, or a pharmaceutically acceptable salt thereof, is formed by the incorporation of any of the normally employed excipients, such as, for example, pharmaceutical grades of mannitol, lactose, starch, pregelatinized starch, magnesium stearate, sodium saccharine, talcum, cellulose ether derivatives, glucose, gelatin, sucrose, citrate, propyl gallate, and the like. Such compositions take the form of solutions, suspensions, tablets, pills, capsules, powders, sustained release formulations, and the like.
Preferably such compositions will take the form of capsule, caplet or tablet and therefore will also contain a diluent such as lactose, sucrose, dicalcium phosphate, and the like; a disintegrant such as croscarmellose sodium or derivatives thereof; a lubricant such as magnesium stearate and the like; and a binder such as a starch, gum acacia, polyvinylpyrrolidone, gelatin, cellulose ether derivatives, and the like.
The compounds of the invention, or their pharmaceutically acceptable salts, may also be formulated into a suppository using, for example, about 0.5% to about 50% active ingredient disposed in a carrier that slowly dissolves within the body, e.g., polyoxyethylene glycols and polyethylene glycols (PEG), e.g., PEG 1000 (96%) and PEG 4000 (4%).
Liquid pharmaceutically administrable compositions can, for example, be prepared by dissolving, dispersing, etc., a compound(s) of the invention (about 0.5% to about 20%), or a pharmaceutically acceptable salt thereof, and optional pharmaceutical adjuvants in a carrier, such as, for example, water, saline, aqueous dextrose, glycerol, ethanol and the like, to thereby form a solution or suspension.
If desired, a pharmaceutical composition of the invention may also contain minor amounts of auxiliary substances such as wetting or emulsifying agents, pH buffering agents, antioxidants, and the like, such as, for example, citric acid, sorbitan monolaurate, triethanolamine oleate, butylated hydroxytoluene, etc.
Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in this art; for example, see Remington""s Pharmaceutical Sciences, 18th Ed., (Mack Publishing Company, Easton, Pa., 1990). The composition to be administered will, in any event, contain a therapeutically effective amount of a compound of the invention, or a pharmaceutically acceptable salt thereof, for treatment of a condition characterized by an abnormality in nitric oxide production in accordance with the teachings of this invention.
The compounds of the invention, or their pharmaceutically acceptable salts, are administered in a therapeutically effective amount which will vary depending upon a variety of factors including the activity of the specific compound employed; the metabolic stability and length of action of the compound; the age, body weight, general health, sex, and diet of the patient; the mode and time of administration; the rate of excretion; the drug combination; the severity of the particular disease-states; and the host undergoing therapy. Generally, a therapeutically effective daily dose is from about 0.14 mg to about 14.3 mg/kg of body weight per day of a compound of the invention, or a pharmaceutically acceptable salt thereof; preferably, from about 0.7 mg to about 10 mg/kg of body weight per day; and most preferably, from about 1.4 mg to about 7.2 mg/kg of body weight per day. For example, for administration to a 70 kg person, the dosage range would be from about 10 mg to about 1.0 gram per day of a compound of the invention, or a pharmaceutically acceptable salt thereof, preferably from about 50 mg to about 700 mg per day, and most preferably from about 100 mg to about 500 mg per day.
E. Preferred Embodiments
Of the compounds of the invention as set forth above in the Summary of the Invention, several groups of compounds are particularly preferred.
One preferred group of compounds are those compounds of formula (I): 
Of this group of compounds, a preferred subgroup of compounds is that subgroup wherein Z1 is xe2x80x94Oxe2x80x94 or xe2x80x94(CH2)mxe2x80x94N(R7) (where m is 0 to 2); Z2 is xe2x80x94Oxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), xe2x80x94Sxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), or xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2); R1 and R3 are independently selected from the group consisting of hydrogen, halo, and alkyl; R2 is hydrogen, alkyl, bromo, iodo, xe2x80x94N(R7)xe2x80x94(CH2)pxe2x80x94N(R8)R9 (where p is 1 to 4), xe2x80x94(CH2)qxe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR8 (where q is 0 to 3), 4-morpholinyl, 1-piperidinyl, 1-piperazinyl, or 1-pyrrolidinyl; R4 is hydrogen or alkyl; R5 is hydrogen, halo, haloalkyl, alkyl, nitro, xe2x80x94OR8, xe2x80x94C(O)OR8, xe2x80x94C(O)N(R8)R9, xe2x80x94N(R8)R9, xe2x80x94N(R8)C(O)R8, or xe2x80x94N(H)S(O)2R10; each R7 is hydrogen or alkyl; and each R8 and R9 is independently hydrogen or alkyl.
Of this subgroup of compounds, a preferred class of compounds is that class wherein Z1 is xe2x80x94Oxe2x80x94; Z2 is xe2x80x94Oxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), xe2x80x94Sxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), or xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2); R1 and R3 are independently selected from the group consisting of hydrogen, chloro, and fluoro; R2 is hydrogen, alkyl, bromo, iodo, xe2x80x94N(R7)xe2x80x94(CH2)pxe2x80x94N(R8)R9 (where p is 1 to 4), xe2x80x94(CH2)qxe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR8 (where q is 0 to 3), 4-morpholinyl, 1-piperidinyl, 1-piperazinyl, or 1-pyrrolidinyl; R4 and R5 are each independently hydrogen or alkyl; and each R7, R8 and R9 is each independently hydrogen or alkyl.
Of this class of compounds, a preferred subclass of compounds is that subclass wherein Z1 and Z2 are both xe2x80x94Oxe2x80x94; R1 and R3 are independently selected from the group consisting of hydrogen, chloro, and fluoro; R2 is hydrogen, alkyl or xe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR8; R4 and R5 are each independently hydrogen or alkyl; and each R7 and R8 is each independently hydrogen or alkyl.
Of this subclass of compounds, preferred compounds are those compounds wherein R1, R2, and R3 are each hydrogen; R4 is hydrogen; and R5 is hydrogen or methyl.
Of these preferred compounds, the most preferred are the compounds selected from the group consisting of the following compounds:
2-(1,3-benzodioxol-5-yloxy)-6-[4-(1H-imidazol-1-yl)phenoxy]pyridine; and
2-(1,3-benzodioxol-5-yloxy)-6-[4-(1H-imidazol-1-yl)-2-methylphenoxy]pyridine; and
2-(1,3-benzodioxol-5-yloxy)-6-[3-(1H-imidazol-1-yl)phenoxy]pyridine.
Of the above-identified subclass of compounds, other preferred compounds are those compounds wherein R1 and R3 are independently fluoro or chloro; R2 is hydrogen, alkyl or xe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR8; R4 is hydrogen; R5 is hydrogen or alkyl; R7 is methyl; and R8 is hydrogen, methyl or ethyl.
Of these preferred compounds, the most preferred are the compounds selected from the group consisting of the following compounds:
2-(1,3-benzodioxol-5-yloxy)-3,5-difluoro-6-[4-(1H-imidazol-1-yl)phenoxy]-4-methylpyridine;
2-(1,3-benzodioxol-5-yloxy)-3,5-difluoro-6-[3-(1H-imidazol-1-yl)phenoxy]-4-methylpyridine; and
2-(1,3-benzodioxol-5-yloxy)-3,5-difluoro-6-[4-(1H-imidazol-1-yl)phenoxy]-4-[(N-methyl-N-((ethoxycarbonyl)methyl)amino]pyridine.
Of the class of compounds described above, a preferred subclass of compounds is that subclass wherein Z1 is xe2x80x94Oxe2x80x94; Z2 is xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2); R1 and R3 are independently selected from the group consisting of hydrogen, chloro, and fluoro; R2 is hydrogen, alkyl or xe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR8; and R4, R5, R7, and R8 are each independently hydrogen or alkyl.
Of this subclass of compounds, preferred compounds are those compounds wherein Z1 is xe2x80x94Oxe2x80x94; Z2 is xe2x80x94N(R7)xe2x80x94CH2xe2x80x94; R1 and R3 are independently selected from the group consisting of hydrogen, chloro, and fluoro; R2 is hydrogen or methyl; R4 and R5 are each independently hydrogen or alkyl; and R7 is hydrogen or alkyl.
Of these preferred compounds, the most preferred compound is 2-(4-(1H-imidazol-1-yl)phenoxy)-3,5-difluoro-4-methyl-6-[((1,3-benzodioxol-5-yl)methyl)amino]pyridine.
Another preferred group of compounds are those compounds of formula (II): 
Of this group of compounds, a preferred subgroup of compounds is that subgroup wherein Z1 is xe2x80x94Oxe2x80x94 or xe2x80x94(CH2)mxe2x80x94N(R7)xe2x80x94 (where m is 0 to 2); Z2 is xe2x80x94Oxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), xe2x80x94Sxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), or xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2); R1 is hydrogen, halo, or alkyl; R4 is hydrogen or alkyl; R5 is hydrogen, halo, haloalkyl, alkyl, nitro, xe2x80x94OR8, xe2x80x94C(O)OR8, C(O)N(R8)R9, xe2x80x94N(R8)R9, xe2x80x94N(R8)C(O)R8, or xe2x80x94N(H)S(O)2R10; R6 is hydrogen, alkyl, aryl, aralkyl, halo, xe2x80x94N(R8)R9, xe2x80x94N(R7)xe2x80x94(CH2)pxe2x80x94N(R8)R9 (where p is 1 to 4), xe2x80x94(CH2)qxe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)OR8 (where q is 0 to 3), 4-morpholinyl, 1-piperidinyl, 1-piperazinyl, or 1-pyrrolidinyl; each R7 is independently hydrogen or alkyl; and each R8 and R9 is independently hydrogen or alkyl.
Of this subgroup of compounds, a preferred class of compounds is that class wherein Z1 and Z2 are both xe2x80x94Oxe2x80x94; R1 is hydrogen, chloro, or fluoro; R4 is hydrogen or alkyl; R5 is hydrogen, halo, haloalkyl or alkyl; R6 is hydrogen, alkyl or xe2x80x94(CH2)qxe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR8 (where q is 0 or 1); R7 is hydrogen or alkyl; and R8 is hydrogen or alkyl.
Of this class of compounds, a preferred subclass of compounds is that subclass wherein R4 is hydrogen; R5 is hydrogen, chloro, fluoro, trifluoromethyl or alkyl; R6 is hydrogen, methyl, or xe2x80x94CH2xe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR8; R7 is hydrogen or methyl; and R8 is hydrogen or alkyl.
Of this subclass of compounds, preferred compounds are those compounds selected from the group consisting of the following compounds:
4-(1,3-benzodioxol-5-yloxy)-2-[4-(1H-imidazol-1-yl)phenoxy]pyrimidine;
4-(1,3-benzodioxol-5-yloxy)-2-[4-(1H-imidazol-1-yl)phenoxy]-6-methylpyrimidine;
4-(1,3-benzodioxol-5-yloxy)-2-[2-fluoro-4-(1H-imidazol-1-yl)phenoxy]-6-methylpyrimidine;
4-(1,3-benzodioxol-5-yloxy)-2-[3-chloro-4-(1H-imidazol-1-yl)phenoxy]-6-methylpyrimidine; and
4-(1,3-benzodioxol-5-yloxy)-2-[3-trifluoromethyl-4-(1H-imidazol-1-yl)phenoxy]-6-methylpyrimidine.
Another preferred group of compounds are those compounds of formula (III): 
Of this group of compounds, a preferred subgroup of compounds is that subgroup wherein Z1 is xe2x80x94Oxe2x80x94 or xe2x80x94(CH2)mxe2x80x94N(R7)xe2x80x94 (where m is 0 to 2); Z3 is xe2x80x94Oxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), xe2x80x94(CH2)nxe2x80x94 (where n is 1 to 4), or xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2); R1 is hydrogen, halo, or alkyl; R4 is hydrogen or alkyl; R5 is hydrogen, halo, haloalkyl, alkyl, nitro, xe2x80x94OR8, xe2x80x94C(O)OR8, xe2x80x94C(O)N(R8)R9, xe2x80x94N(R8)R9, xe2x80x94N(R8)C(O)R8, or xe2x80x94N(H)S(O)2R10; R6 is hydrogen, alkyl, aryl, aralkyl, halo, xe2x80x94N(R8)R9, xe2x80x94N(R7)xe2x80x94(CH2)pxe2x80x94N(R8)R9 (where p is 1 to 4), xe2x80x94(CH2)qxe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)OR8 (where q is 0 to 3), 4-morpholinyl, 1-piperidinyl, 1-piperazinyl, or 1-pyrrolidinyl; each R7 is hydrogen or alkyl; and each R8 and R9 is independently hydrogen or alkyl.
Of this subgroup of compounds, a preferred class of compounds is that class wherein Z1 is xe2x80x94Oxe2x80x94; Z3 is xe2x80x94Oxe2x80x94 or xe2x80x94CH2xe2x80x94; R1 is hydrogen, chloro, fluoro or methyl; R4 and R5 are independently hydrogen or alkyl; R6 is hydrogen, alkyl, halo, 4-morpholinyl, xe2x80x94N(R7)xe2x80x94(CH2)pxe2x80x94N(R8)R9 (where p is 1 to 4), or xe2x80x94(CH2)qxe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR8 (where q is 0 to 3); and each R7, R8, and R9 is hydrogen or alkyl.
Of this class of compounds, a preferred subclass of compounds is that subclass wherein R1 is hydrogen or methyl; and R6 is hydrogen, methyl, chloro, fluoro, 4-morpholinyl or xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94N(R8)R9 (where m is 1 to 4).
Of this subclass of compounds, preferred compounds are those compounds wherein R4 is hydrogen; R5 is hydrogen; R7 is hydrogen or methyl; and R8 and R9 are independently hydrogen or methyl.
Of these preferred compounds, most preferred compounds are those compounds selected from the group consisting of the following compounds:
2-(1,3-benzodioxol-5-yloxy)-4-[4-(1H-imidazol-1-yl)phenoxy]pyrimidine;
2-(1,3-benzodioxol-5-yloxy)-4-[4-(1H-imidazol-1-yl)phenoxy]-5-methylpyrimidine;
2-[(1,3-benzodioxol-5-yl)methyl]-6-chloro-4-[4-(1H-imidazol-1-yl)phenoxy]pyrimidine;
2-[(1,3-benzodioxol-5-yl)methyl]-6-[3-(dimethylamino)propyl(methyl)amino]-4-[4-(1H-imidazol-1-yl)phenoxy]-5-methylpyrimidine; and
2-[(1,3-benzodioxol-5-yl)methyl]-4-[4-(1H-imidazol-1-yl)phenoxy]-6-(morpholin-4-yl)pyrimidine.
Another preferred group of compounds are compounds of formula (IV): 
Of this preferred group of compounds, a preferred subgroup of compounds is that subgroup wherein Z1 is xe2x80x94Oxe2x80x94 or xe2x80x94(CH2)mxe2x80x94N(R7)xe2x80x94 (where m is 0 to 2); Z2 is xe2x80x94Oxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), xe2x80x94Sxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), or xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2); R1 is hydrogen, halo, or alkyl; R4 is hydrogen or alkyl; R5 is hydrogen, halo, haloalkyl, alkyl, nitro, xe2x80x94OR8, xe2x80x94C(O)OR8, xe2x80x94C(O)N(R8)R9, xe2x80x94N(R8)R9, xe2x80x94N(R8)C(O)R8, or xe2x80x94N(H)S(O)2R10; R6 is hydrogen or alkyl; each R7 is hydrogen or alkyl; and each R8 and R9 is independently hydrogen or alkyl.
Of this subgroup of compounds, a preferred class of compounds is that class wherein Z1 and Z2 are both xe2x80x94Oxe2x80x94; R1 is hydrogen, chloro, or fluoro; and R4, R5, and R6 are independently hydrogen or alkyl.
Of this class of compounds, a preferred compound is 6-(1,3-benzodioxol-5-yloxy)-4-[4-(1H-imidazol-1-yl)phenoxy]pyrimidine.
F. Preparation of the Compounds of the Invention
As a matter of convenience, the following description of the preparation of the compounds of the invention is directed to the preparation of compounds of formula (I) and compounds of formula (III). It is understood, however, that similar synthetic methods may be used to prepare the corresponding compounds of formula (II) and (IV).
1. Preparation of Compounds of formula (C)
Compounds of formula (C) are intermediates used in the preparation of compounds of formula (I) as set forth above in the Summary of the Invention, and are prepared as described below in Reaction Scheme 1 where each X is independently fluoro or chloro, R1 and R3 are independently selected from the group consisting of hydrogen, halo, alkyl, haloalkyl, nitro, aralkoxy, xe2x80x94OR8, xe2x80x94R11xe2x80x94OR8, xe2x80x94N(R8)R9, xe2x80x94C(O)OR8, xe2x80x94R11xe2x80x94C(O)OR8, xe2x80x94C(O)N(R8)R9, xe2x80x94R11xe2x80x94C(O)N(R8)R9, xe2x80x94C(O)N(R8)CH2C(O)N(R8)R9, xe2x80x94N(R8)C(O)N(R8)R9, xe2x80x94N(R8)C(O)R9, xe2x80x94N(R8)S(O)2R10, and xe2x80x94N(R8)C(O)N(R8)xe2x80x94CH2C(O)N(R8)R9 (where each R8, R9, R10 and R11 are as described above in the Summary of the Invention); R2 is hydrogen, bromo, iodo, alkyl, 4-morpholinyl, 1-piperidinyl, 1-piperazinyl, 1-pyrrolidinyl, xe2x80x94N(R7)xe2x80x94(CH2)pxe2x80x94N(R8)R9 (where p is 1 to 4 and R7, R8 and R9 are as described above in the Summary of the Invention) or xe2x80x94(CH2)qxe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR8 (where q is 0 to 3 and R7 and R8 are as described above in the Summary of the Invention); and Z2 is xe2x80x94Oxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), xe2x80x94Sxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), or xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2): 
Compounds of formula (A) are commercially available, for example, from Aldrich Chemical Co., or can be prepared either according to methods known to those of ordinary skill in the art or according to the methods disclosed in U.S. Pat. No. 5,691,364 (Buckman et al.). Compounds of formula (B) are commercially available, for example, from Aldrich Chemical Co, or can be prepared according to methods known to those of ordinary skill in the art.
In general, compounds of formula (C) are prepared by first treating a solution of an equimolar amount of a compound of formula (A) and an equimolar amount of a compound of formula (B) in an aprotic solvent, such as dimethyl sulfoxide, with a base, preferably cesium carbonate. The resulting mixture is heated to between about 0xc2x0 C. and about 60xc2x0 C., preferably at about 50xc2x0 C., for about 8 to about 18 hours, preferably for about 18 hours. The compound of formula (C) is then isolated from the reaction mixture by standard isolation techniques, such as extraction of the organic layer and in vacuo removal of the solvent.
In addition to the compounds of formula (A) as described above, similar compounds may be used in the above Reaction Scheme to produce corresponding compounds of formula (C). For example, compounds of formula (Aa), compounds of formula (Ab) and compounds of formula (Ac), as depicted below: 
where each X and R1 are the same as described above for compounds of formula (A) and R6 is the same as described above in the Summary of the Invention, may be reacted with compounds of formula (B) as described above, to form the corresponding compounds of formula (C). Compounds of formula (Aa), compounds of formula (Ab) and compounds of formula (Ac) are commercially available, e.g., from Aldrich Chemical Co., or either may be prepared according to methods known to one of ordinary skill in the art or according to methods as described in U.S. Pat. No. 5,691,364 (Buckman et al.).
2. Preparation of compounds of formula (G)
Compounds of formula (G) are intermediates used in the preparation of compounds of formula (III) as set forth above in the Summary of the Invention, and are prepared as described below in Reaction Scheme 2 where X1 and X2 are the same and halo; R1a is hydrogen, alkyl, aralkoxy, xe2x80x94OR8, xe2x80x94R11xe2x80x94OR8, xe2x80x94C(O)OR8, or xe2x80x94R11xe2x80x94C(O)OR8; R12 is alkyl or aralkyl; and Z3 is xe2x80x94(CH2)nxe2x80x94 (where n is 1 to 4): 
Compounds of formula (D) and compounds of formula (E) are commercially available, for example, from Aldrich Chemical Co., or may be prepared according to methods known to those of ordinary skill in the art.
In general, compounds of formula (G) are prepared by first dissolving a compound of formula (D) and an equimolar amount of a compound of formula (E) in a protic solvent, such as ethanol, in the presence of an excess amount of a metal alkoxide, such as sodium methoxide. The resulting mixture is allowed to reflux for between 4 and 6 hours, preferably for about 5 hours. The solvent is removed in vacuo and the resulting residue is dissolved in water, washed with ethyl acetate, treated with charcoal and acidified, for example, by the addition of a strong acid such as HCl. The compound of formula (F) is isolated from the residue by standard isolation techniques, such as filtration and removal of impurities.
A compound of formula (F) is then treated with an excess amount of a halogenating agent, such as phosphorus oxychloride, with a co-solvent, such as N,N-diethylaniline. The resulting mixture is heated to between about 35xc2x0 C. and about 50xc2x0 C., preferably to about 45xc2x0 C., for about 2 to 6 hours, preferably for about 3 hours. The solvent is then removed in vacuo and the resulting residue is added to ice. The compound of formula (G) is isolated from the residue by standard isolation techniques, such as filtration and crystallization from an organic solvent, such as hexane.
Alternatively, compounds of the following formula: 
where R12 and R1a are defined above for the compounds of formula (D) and R13 is hydrogen, alkyl, aryl or aralkyl, may be treated with compounds of formula (E), as described above, under standard primary synthesis conditions of pyrimidines known to those of ordinary skill in the art to form corresponding mono-hydroxy compounds of formula (F). These compounds may then be treated under similar halogenating conditions as described above for compounds of formula (F) in the foregoing Reaction Scheme to form corresponding compounds of formula (G) where X1 is halo and X2 is hydrogen, alkyl, aryl or aralkyl.
Alternatively, compounds of formula (G), as described above where X2 is halo, may be treated with a hydrogenating agent under standard hydrogenation conditions known to those of ordinary skill in the art to form the corresponding compounds of formula (G) where X2 is hydrogen.
Alternatively, compounds of formula (F) where R1a is hydrogen may be treated with a nitrating agent under standard nitration conditions to form compounds of formula (F) where R1a is nitro. These compounds can then be treated in a similar manner as compounds of formula (F) in Reaction Scheme 2 above to form compounds of formula (G) where R1a is nitro, when can then be treated in a similar manner as described below in Reaction Scheme 4 to form compounds of formula (IIIa) and formula (IIIb) where R1a is nitro. These compounds can then be treated under standard reduction conditions to form compounds of formula (IIIa) and formula (IIIb) where R1a is xe2x80x94N(R8)R9 where R8 and R9 are described above in the Summary of the Invention.
3. Preparation of compounds of formula (Ia)
Compounds of formula (Ia) are compounds of formula (I) as set forth above in the Summary of the Invention, and are prepared as described below in Reaction Scheme 3 wherein X is fluoro or chloro; R1 and R3 are independently selected from the group consisting of hydrogen, halo, alkyl, haloalkyl, nitro, aralkoxy, xe2x80x94OR8, xe2x80x94R11xe2x80x94OR8, xe2x80x94N(R8)R9, xe2x80x94C(O)OR8, xe2x80x94R11xe2x80x94C(O)OR8, xe2x80x94C(O)N(R8)R9, xe2x80x94R11xe2x80x94C(O)N(R8)R9, xe2x80x94C(O)N(R8)CH2C(O)N(R8)R9, xe2x80x94N(R8)C(O)N(R8)R9, xe2x80x94N(R8)C(O)R9, xe2x80x94N(R8)S(O)2R10, and xe2x80x94N(R8)C(O)N(R8)xe2x80x94CH2C(O)N(R8)R9 (where each R8, R9, R10 and R11 are as described above in the Summary of the Invention); R2 is hydrogen, bromo, iodo, alkyl, 4-morpholinyl, 1-piperidinyl, 1-piperazinyl, or 1-pyrrolidinyl, xe2x80x94N(R7)xe2x80x94(CH2)pxe2x80x94N(R8)R9 (where p is 1 to 4 and R7, R8 and R9 are as described above in the Summary of the Invention) or xe2x80x94(CH2)qxe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)xe2x80x94OR8 (where q is 0 to 3 and R7 and R8 are as described above in the Summary of the Invention); R4 is hydrogen or alkyl; R5 is hydrogen, halo, haloalkyl, alkyl, nitro, xe2x80x94OR8, xe2x80x94C(O)OR8, xe2x80x94C(O)N(R8)R9, xe2x80x94N(R8)R9, xe2x80x94N(R8)C(O)R8, or xe2x80x94N(H)S(O)2R10; Z1 is xe2x80x94(CH2)mxe2x80x94Oxe2x80x94 (where m is 0 to 2), xe2x80x94(CH2)mxe2x80x94Sxe2x80x94 (where m is 0 to 2), or xe2x80x94(CH2)mxe2x80x94N(R7)xe2x80x94 (where m is 0 to 2); and Z2 is xe2x80x94Oxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), xe2x80x94Sxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), or xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2): 
Compounds of formula (H) are commercially available or may be prepared according to methods known to those of ordinary skill in the art. Compounds of formula (C) are prepared according to methods described herein.
In general, compounds of formula (Ia) are prepared by treating a compound of formula (H) in an aprotic solvent, such as dimethyl sulfoxide, with an equimolar amount of a compound of formula (C) in the presence of a base, such as cesium carbonate. The mixture is heated to between 40xc2x0 C. and 100xc2x0 C., preferably to about 90xc2x0 C., for a period of time sufficient to complete the reaction, preferably for about 18 hours. The compound of formula (Ia) is then isolated from the reaction mixture by standard isolation techniques, such as extraction, in vacuo removal of the solvent and flash chromatography.
In a similar manner, other compounds of the invention may be prepared. For example, compounds of formula (Aa), formula (Ab) and formula (Ac), as depicted above, may be used to prepare the corresponding compounds of formula (C), as described above, which can then be treated with compounds of formula (H), as described above, to prepare compounds of formula (II), formula (III) and formula (IV) as described above in the Summary of the invention.
4. Preparation of compounds of formula (IIIa)
Compounds of formula (IIIa) are compounds of formula (III) as set forth above in the Summary of the Invention, and are prepared as described below in Reaction Scheme 4 wherein X1 and X2 are the same and halo; R1a is hydrogen, alkyl, nitro, aralkoxy, xe2x80x94OR8, xe2x80x94R11xe2x80x94OR8, xe2x80x94N(R8)R9, xe2x80x94C(O)OR8, xe2x80x94R11xe2x80x94C(O)OR8, or xe2x80x94N(R8)S(O)2R10; R4 is hydrogen or alkyl; R5 is hydrogen, halo, haloalkyl, alkyl, nitro, xe2x80x94OR8, xe2x80x94C(O)OR8, xe2x80x94C(O)N(R8)R9, xe2x80x94N(R8)R9, xe2x80x94N(R8)C(O)R8, or xe2x80x94N(H)S(O)2R10; R6a is hydrogen, alkyl, aryl, aralkyl, halo, xe2x80x94N(R8)R9, xe2x80x94N(R7)xe2x80x94(CH2)pxe2x80x94N(R8)R9 (where p is 1 to 4), xe2x80x94(CH2)qxe2x80x94N(R7)xe2x80x94CH2xe2x80x94C(O)OR8 (where q is 0 to 3), 4-morpholinyl, 1-piperidinyl, 1-piperazinyl, or 1-pyrrolidinyl (where each p, q, R8, R9 and R10 are as described above in the Summary of the invention); Z1 is xe2x80x94(CH2)mxe2x80x94Oxe2x80x94 (where m is 0 to 2), xe2x80x94(CH2)mxe2x80x94Sxe2x80x94 (where m is 0 to 2), or xe2x80x94(CH2)mxe2x80x94N(R7)xe2x80x94 (where m is 0 to 2); and Z3 is xe2x80x94(CH2)nxe2x80x94 (where n is 1 to 4), xe2x80x94Oxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), xe2x80x94Sxe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2), or xe2x80x94N(R7)xe2x80x94(CH2)mxe2x80x94 (where m is 0 to 2); 
Compounds of formula (H) are commercially available or may be prepared according to methods known to those skilled in the art. Compounds of formula (G) are prepared according to methods disclosed herein.
In general, compounds of formula (IIIa) are prepared by treating a compound of formula (H) with a compound of formula (G) in a similar manner as described above for the treatment of a compound of formula (H) with a compound of formula (C) to prepare a compound of formula (Ia). The resulting compound of formula (IIIa) is treated with a compound of formula HR6a (where R6a is as described above) in an aprotic solvent, such as dimethyl sulfoxide. The resulting mixture is heated to between about 40xc2x0 C. and about 100xc2x0 C., preferably to about 40xc2x0 C., for about 12 to about 24 hours, preferably for about 18 hours. The compound of formula (IIIb) is then isolated from the reaction mixture by standard isolation techniques, such as extraction, in vacuo removal of the solvent and crystallization.
Alternatively, compounds of formula (G) where X1 is halo and X2 is hydrogen or alkyl, prepared as described above in Reaction Scheme 2, may be treated with compounds of formula (H), under similar conditions as described above, to prepared compounds of formula (III) where R6 is hydrogen or alkyl.
Compounds of formula (IIIa) and formula (IIIb) where R1a is hydroxy or alkyl may be treated with an appropriate halogenating agent under standard conditions to form corresponding compounds of formula (IIIa) and formula (IIIb) where R1a is halo or haloalkyl, respectively. Alternatively, compounds of formula (IIIa) and formula (IIIb) where R1a is xe2x80x94N(R8)R9xe2x80x94, xe2x80x94C(O)OR8, xe2x80x94R11xe2x80x94C(O)OR8 may be treated under standard alkylation, acylation or condensation conditions known to those of ordinary skill in the art to form compounds of formula (IIIa) and formula (IIIb) where R1a is xe2x80x94C(O)N(R8)R9, xe2x80x94R11xe2x80x94C(O)N(R8)R9, xe2x80x94C(O)N(R8)CH2C(O)N(R8)R9, xe2x80x94N(R8)C(O)N(R8)R9 and xe2x80x94N(R8)C(O)R9.
All compounds of the invention as prepared above which exist in free base or acid form may be converted to their pharmaceutically acceptable salts by treatment with the appropriate inorganic or organic base or acid. Salts of the compounds prepared above may be converted to their free base or acid form by standard techniques.